Risk Factors and Progression of Keratoconus

NCT05676580 | Recruiting

• 1 other identifier: RECHMPL20_0450 / UF8090
• Study Type: interventional
• Target: 200
• Locations: 1 country
• Sites: 1

Brief Summary

Primary objective : Description of keratoconus at baseline and during progression in 200 participants followed by the ophthalmology departments of CHU Montpellier, CHU Bordeaux and CHU Toulouse during a 2-year period. Clinical outcome, histology of the cornea and tears proteomics will be assessed in 4 groups at different points in time:

• At 6 months in participants with no intervention (risk reduction instructions: not to rub their eyes)
• At 6 months in participants with no intervention that didn't comply with the risk reduction instructions
• At 1 month in participants assigned to cross-linking surgery
• At 1 month in participants assigned to intra corneal ring surgery If both eyes are affected, both will be evaluated with their own visit agenda. Visits for no surgery participants will be set at 6 months, 12 months and 24 months in the absence of intervention (apart from the behavioral risk reduction). Visits for surgery participants will be set at D7, 1 month, 6 months, 12 months and 24 months after the procedure: cross-linking or placement of the intra corneal ring. Secondary objective : Description of the association between clinical outcomes, histological progression of the cornea and tears proteomics in time, 2 years period. Comparison of tears proteomics in 36 participants with keratoconus followed at CHU of Montpellier and healthy participants at baseline .

Conditions

Keratoconus

Outcome Measures

Primary Outcomes (11)

• Keratoconus clinical progression (Keratometry map)

  Modelisation of refraction measurements in diopters, by corneal elevation topography (Orbscan and Pentacam), giving an additional indicator of the corneal deformity. High values of diopter correspond to positive bulges of the cornea. A topographic axial map will be acquired to monitor minimal and maximal keratometry. These measurements will be taken at baseline and compared for reference of progression at each visit for each eye. Keratoconus definition according to Rabinowitz (Rabinowitz YS, 1989) criteria: * Corneal asymmetry greater than 1.5 diopters (D), between the upper and lower part of the cornea, on the median vertical axis. * Central corneal power (Kmax) \> 47.2 D, measured at the top of the cone. * Asymmetry of central keratometry \> 1D between the two eyes

  Baseline vs Visit at 1 month/6 months/12 months/24 months

• Keratoconus clinical progression (Pachymetric map)

  Thickness of the cornea will be assessed in microns (µm) at several locations and will be presented as a map by corneal elevation topography (Orbscan and Pentacam). The pachymetric map will be acquired at baseline and compared for reference of progression at each visit for each eye. The higher and lower thickness points will be notified for the anterior and posterior parts of the eye.

  Baseline vs Visit at 1 month/6 months/12 months/24 months

• Keratoconus clinical progression (Visual acuity test)

  Visual acuity test with and without correction: decimal and Parinaud scales secondarily translated in LogMar.

  Baseline vs Visit at 1 month/6 months/12 months/24 months

• Keratoconus clinical progression (Biomicroscopic examination of the cornea)

  A biomicroscopic examination of the cornea in search of signs that may modify the therapeutic indications i.e : Fleischer rings (iron deposits in the lower part of the bulge, due to the stagnation of tears), visible corneal nerves, corneal opacities (due to scar tissue)

  Baseline vs Visit at 1 month/6 months/12 months/24 months

• ABCD grading of keratoconus

  Grading of the keratoconus, according to the ABCD classification : * A: keratometry of the anterior surface of the cornea (Anterior radius of curvature (ARC)), in the area of 3 mm centered by the thinnest point. * B: keratometry of the posterior surface of the cornea (Back or posterior radius of curvature PRC), in the 3mm area centered by the thinnest point. * C: thinnest point of the Cornea, i.e. minimum pachymetry. * D: Distance best corrected vision: visual acuity with the best correction, measured in 10° or in the Parinaud scale.

  Baseline vs Visit at 1 month/6 months/12 months/24 months

• Keratoconus histological progression - Confocal microscopy (tissue thickness)

  Histological degradation of the cornea taken at baseline for reference. The confocal microscope allows longitudinal analysis making it possible to carry out comparative qualitative and quantitative analyzes of the corneal tissue during time. In keratoconus, this technique is possible to highlight a reduction in basal plexus nerve density and poorer anterior stromal cell density compared to healthy subjects. Tissue thickness in microns (µm)

  Baseline vs Visit at 1 month/6 months/12 months/24 months

• Keratoconus histological progression - Confocal microscopy (Cellular organization)

  Histological degradation of the cornea taken at baseline for reference. The confocal microscope allows longitudinal analysis making it possible to carry out comparative qualitative and quantitative analyzes of the corneal tissue during time. In keratoconus, this technique is possible to highlight a reduction in basal plexus nerve density and poorer anterior stromal cell density compared to healthy subjects. Cell organization and morphology. Image acquisition. * Colonization by inflammatory cells (yes/no), increased nucleo/cytoplasmic ratio (yes/no), hyperreflectivity of the nuclei (yes/no). * Nerve density of the basal plexuses of normal appearance (yes/no), straight with branches (yes/no), normal hyperreflectivity (yes/no)

  Baseline vs Visit at 1 month/6 months/12 months/24 months

• Keratoconus histological progression - Confocal microscopy (Cellular density)

  Histological degradation of the cornea taken at baseline for reference. The confocal microscope allows longitudinal analysis making it possible to carry out comparative qualitative and quantitative analyzes of the corneal tissue during time. In keratoconus, this technique is possible to highlight a reduction in basal plexus nerve density and poorer anterior stromal cell density compared to healthy subjects. Cellular density (number). Image acquisition. \- Cell count in the different layers, corneal nerve count from the basal plexus to the corneal apex

  Baseline vs Visit at 1 month/6 months/12 months/24 months

• Keratoconus histological progression - Confocal microscopy (Light scattering)

  Histological degradation of the cornea taken at baseline for reference. The confocal microscope allows longitudinal analysis making it possible to carry out comparative qualitative and quantitative analyzes of the corneal tissue during time. In keratoconus, this technique is possible to highlight a reduction in basal plexus nerve density and poorer anterior stromal cell density compared to healthy subjects. Light scattering in vivo, measurement of corneal deformity. Diopter.

  Baseline vs Visit at 1 month/6 months/12 months/24 months

• Risk factors - Questionnaire

  * Presence of atopy/allergy * Eye rubbing * Family medical history * Ethnicity * Smoking habits * Dry eye syndrome

  Baseline vs 24 months

• Tears proteomics

  For 36 participants from Montpellier. Composition and evolution of tears determined by proteomic analysis

  Baseline vs Visit at 1 month/6 months

Secondary Outcomes (3)

• ABCD class worsening between consultations

  Baseline vs Visit at 1 month/6 months - Baseline vs 12 months - Baseline vs 24 months

• Keratoconus histological evolution

  Baseline vs Visit at 1 month/6 months

• Proteomic profile evolution

  Baseline vs Visit at 1 month/6 months

Study Arms (2)

Abstention

OTHER

After keratoconus diagnosis the patient won't be assigned to intervention

Other: abstention

Intervention (cross-linking surgery or intra corneal ring)

OTHER

After keratoconus diagnosis the patient was assigned to cross linking surgery or intra corneal ring surgery

Procedure: cross-linking surgery or intra corneal ring

Interventions

cross-linking surgery or intra corneal ring PROCEDURE

After keratoconus diagnosis the patient was assigned to surgery

Intervention (cross-linking surgery or intra corneal ring)

abstention OTHER

No surgery

Abstention

Eligibility Criteria

• Age: 10 Years - 40 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Participants with clinical keratoconus (Rabinowitz criteria with topographic slit lamp abnormalities and visual impairment), preclinical or crude keratoconus (abnormal or suspicious topography with normal slit lamp examination and normal visual acuity, visual acuity)
• Followed by the ophthalmology services of the CHU Montpellier, CHU Bordeaux or CHU Toulouse
• For adult Participants: collection of written informed consent, after a period of reflection period
• For minors: informed consent signed by at least one of the 2 parents or legal representatives legal representatives, and assent of the child after a period of reflection
• Affiliation to the French social security system or beneficiary of such a system

You may not qualify if:

• Person under legal supervision, guardianship or curator
• History of corneal implant on both eyes
• Planned relocation before the end of the first stage of treatment (abstention, cross-linking, intra-corneal ring depending on the participant)

Sponsors & Collaborators

• University Hospital, Montpellier: lead

Study Sites (1)

CHU Gui de Chauliac - Service d'Ophtamologie

Montpellier, Occitanie, 34295, France

RECRUITING

MeSH Terms

Conditions

Keratoconus

Condition Hierarchy (Ancestors)

Corneal Diseases; Eye Diseases

Study Officials

• Vincent DAIEN, PR

  CHU Monptellier

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Vincent DAIEN, PR

CONTACT

0673055877; v-daien@chu-montpellier.fr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: HEALTH SERVICES RESEARCH
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 18, 2022
• First Posted: January 9, 2023
• Study Start: June 5, 2023
• Primary Completion (Estimated): June 5, 2027
• Study Completion (Estimated): May 1, 2028
• Last Updated: September 5, 2025

Record last verified: 2025-08

Locations

FR (1)